title: A comparison of the tumors induced by coal tar and benzo[a]pyrene in a 2-year bioassay.
abstract: The tumorigenicity of two coal tar mixtures was compared to that of benzo[a]pyrene after 2 years of feeding. Mixture 1, a composite of coal tar from seven coal gasification plant waste sites, was fed to female B6C3F1 mice (48 mice per group) for 2 years at doses of 0.0, 0.01, 0.03, 0.1, 0.3, 0.6 and 1.0%. Mixture 2, which was composed of coal tar from two of the seven waste sites and another site having a high benzo[a]pyrene content, was fed at doses of 0.0, 0.03, 0.1 and 0.3%. Additional groups of mice were fed 0, 5, 25 and 100 ppm benzo[a]pyrene. The coal tar diets induced a dose-related increase in hepatocellular adenomas and carcinomas, alveolar/bronchiolar adenomas and carcinomas, forestomach squamous epithelial papillomas and carcinomas, small intestine adenocarcinomas, histiocytic sarcomas, hemangiosarcomas in multiple organs and sarcomas. Benzo[a]pyrene treatment resulted in an increased incidence of papillomas and/or carcinomas of the forestomach, esophagus and tongue. A comparison of the results indicated that the benzo[a]pyrene in the coal tar diets could be responsible for the forestomach tumors. In contrast, the lung and liver tumors appeared to be due to other genotoxic components contained within the coal tar mixture, while the small intestine tumors resulted from chemically-induced cell proliferation that occurred at high doses of coal tar.
authors.affiliation: National Center for Toxicological Research, Jefferson, AR 72079, USA. SCULP@NCTR.FDA.GOV
authors.forename: S J
authors.initials: SJ
authors.lastname: Culp
authors.forename: D W
authors.initials: DW
authors.lastname: Gaylor
authors.forename: W G
authors.initials: WG
authors.lastname: Sheldon
authors.forename: L S
authors.initials: LS
authors.lastname: Goldstein
authors.forename: F A
authors.initials: FA
authors.lastname: Beland
mesh_terms: D000236:Adenoma / Q000139:chemically induced; D000818:Animals; D001564:Benzo(a)pyrene / Q000008:administration & dosage / Q000633:toxicity*; D001681:Biological Assay; D002277:Carcinoma / Q000139:chemically induced; D003033:Coal Tar / Q000008:administration & dosage / Q000737:chemistry / Q000633:toxicity*; D004032:Diet; D005260:Female; D007220:Industrial Waste; D007414:Intestinal Neoplasms / Q000139:chemically induced; D008113:Liver Neoplasms / Q000139:chemically induced; D008175:Lung Neoplasms / Q000139:chemically induced; D051379:Mice; D008815:Mice, Inbred Strains; D009374:Neoplasms, Experimental / Q000139:chemically induced* / Q000473:pathology; D010212:Papilloma / Q000139:chemically induced; D011083:Polycyclic Compounds / Q000633:toxicity; D012513:Sarcoma, Experimental / Q000139:chemically induced; D013274:Stomach Neoplasms / Q000139:chemically induced; D013997:Time Factors
chemical_list: D007220:Industrial Waste; D011083:Polycyclic Compounds; D001564:Benzo(a)pyrene; D003033:Coal Tar